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SustainabilitySustainability is a relatively new word in the vocabulary of America’s civic dialog. For many it has become a buzzword in lively discussions of urban transport but it still has only fuzzy meaning for most citizens and professionals. What does urban transportation sustainability really mean? In Europe the concept has been discussed in some depth over the last decade. What meanings are attached to it there? What does it mean for the good citizens of the U.S.? The essence of sustainability is captured in this: projects that we undertake today should not deplete resources that we diminish prospects for future generations. To measure this a full accounting of environmental impacts must be included. It is now evident that mere emissions of carbon dioxide collectively are changing our world climate, and therefore our ecosystems and livelihoods. Indeed, sustainability can be applied to the whole of humanity on this planet. |
The measurement of urban transportation sustainability should include the value of time. Every year the Texas Transportation Institute updates its estimates of passenger-hours wasted in the chronic congestion that plagues American cities and towns. In large cities, this reaches 60 hours per person. TTI estimates that $78 billion dollars was wasted in lost hours and burnt fuel in 2007. That’s extra cost due to congestion -- not the total driving cost!


Is America’s carbon-polluting highway policy that generates long driving distances congestion sustainable?
Sustainable transportation policies encourage greener travel that is less carbon-emitting. They should move most every-day mobility onto an electric grid of some sort. They should encourage walking and biking for local travel and access to regional transit stations. Public transport, pedestrian travel, and biking all have prominent parts in transportation sustainability. Now they can be assisted by better transit services with APMs, including more advanced taxi-like versions known as Personal Rapid Transit (PRT).
In England and Sweden, coalitions of sustainability-minded citizens have formed implement higher-order APMs known as PRT. Based in Stockholm, the Institute for Sustainable Transportation leads planning studies aimed at attracting a significant share of urban travel to their version of PRT dubbed podcars. A review of studies there indicates that taxi-like transit services can attract a much higher mode share. The European Union’s CityMobil program is paying close attention to PRT developments and their potential.
Sustainable transportation is a vast topic awaiting your Google searches. To urban analysts, it is really about mode split. What percentage of travel is by private vehicle – which have become large SUVs and pickups that overwhelm older districts? In the U.S. overall, urban mobility is over 95 percent by highway! Public transport overall accounts for only 2-3 percent of urban travel. In older, denser cities, the shares of walking and transit are much higher – 10-15% in the most transit-oriented cities. In Europe and Asia, they are even higher.
Urban transportation comprises a wide range of programs and policies – traffic and parking management, road improvements, cleaning and snow removal, etc. For balance, it should have preferential support for green modes – walking, biking and transit. Are there sidewalks? Are they maintained? Who does the landscaping? What are the more specialized niches for paratransit, mobility carts, and segways?
How can travel be optimized to be more sustainable? To get answers to these intriguing questions, come to the Upstate New York town of Ithaca, home to Cornell University, this September for Podcar City II. Ithaca has become a vital center of PRT thinking and podcar action for sustainable transportation. You might also join ATRA, as this will gain you a $100 rebate.

